JP2016503727A - Cold valley bottom rolling device - Google Patents

Abstract

An apparatus 20 for rolling the valley bottom on the thread T of the object O is screwed into the main body 21, an accumulator piston 24 mounted for sealing and sliding in the passage 22 of the main body, and the main body. A coarse adjustment screw 25, a Belleville spring stack 26 compressed between the coarse adjustment screw and the accumulator piston, and an actuator piston mounted for sealing and sliding within the cylindrical opening 23 of the body. 28A or 28B and a screw roll 32 rotatably mounted on the actuator piston. The fine adjustment screw is threaded 34 into the first opening 34 of the body and communicates with the fluid chamber between the accumulator and the actuator piston. The position of the coarse and fine adjustment screws can be selectively adjusted to controllably change the fluid pressure in the chamber. The device can be attached to the machine tool 35 and selected towards the object to perform valley bottom rolling on the object screw when the object and the device are rotated relative to each other. Can be moved.

Description

  The present invention relates generally to an apparatus for burnishing a round bottom of a screw valley (eg, for pipes used in the oil industry), and more particularly to an improved cold valley bottom rolling apparatus.

  In the petroleum industry, pipes are screwed together to form a drill string (ie, pipes connected in series). However, as the applications for large excursion drilling, multilateral wells, and horizontal wells become more prominent, the stress and bending moment on the thread connection of the drill string increases. Increasing the number of pipe connections and increasing stress increases the risk of downhole damage to the drill string. The cost of repairing one downhole damage can exceed $ 1 million.

  Cold valley bottom rolling is the process of burnishing the freshly or previously cut thread root rounding of the rotary shoulder connection. A hardening roll having a profile similar to that of the screw to be burned is pressed against the rounded portion of the bottom of the screw and brought into contact therewith. Pressure is applied to push the curing roll into the cut surface of the rounded bottom. This causes the material to deform and cold work, improve the surface finish of the screw, and compress and move the valley material particles.

  Industry experience has suggested that cold valley bottom rolling can extend the fatigue life of screw connections 3 to 5 times over similar untreated connections under the same operating conditions. Several studies mention laboratory results that suggest that fatigue life can be improved up to 27 times by the cold valley bottom rolling process. For example, see Non-Patent Document 1. These various studies attributed the increase in fatigue life to one or more of the following factors:

  (1) Cold valley bottom rolling creates a thin area of compressive residual stress in the valley region of the screw. This compressive residual stress cancels the tensile stress that occurs during use, and lowers the overall stress in the critical stress area of the thread root.

  (2) The smooth and hard roll burnishing effect flattens small scratches and ridges remaining after threading operations to a more uniform surface. The tip of these scratches is sharp and is considered to be a large stress concentration source. As a result, these scratches appear to be crack propagation points for fatigue damage.

  (3) The flaw becomes the main position of chemical corrosion. The microscopic surface of the wound is very jagged and porous. This exposes large surface areas and many molecular binding sites to the effects of liquid and gas corrosion within the drill string environment. Burnishing smoothes this surface and reduces exposure and inclusions. This helps to reduce surface area and compress to high density.

  (4) Cold valley bottom rolling has a work hardening effect on the material surface. At the atomic scale, it is believed that the crystal structure changes from a repetitive and uniform atomic structure to a structure with many dislocation patterns due to compressive displacement of the crystal lattice within the grain structure of steel. These dislocations are believed to combine crystal structures and become more resistant to further deformation. This increased resistance to further deformation helps to prevent cracks from starting and further prevents microcracks from growing into structural defects that can jeopardize the integrity of the joint. To help. Laboratory studies have shown that cracks produced at cold rolled joints have a fairly small crack aspect ratio (ie, the ratio of crack length to crack depth). The reduction of this ratio from 30% to 50% means that cracks occurring at cold rolled joints tend to be deep and short rather than long and shallow. Long and shallow cracks tend to lead to sudden and complete structural failure of the joint. Deep cracks partially entering the compartment wall can be detected by the pressure drop of the circulating drilling fluid, thereby prematurely destroying the damaged drill string before the joint is completely structurally damaged. It becomes possible to repair.

  Because of the aforementioned advantages, cold valley bottom rolling is commonly practiced on many new and recut screws currently used in drill string pipes used in the oil industry. This is a cost saving process. This can dramatically extend the fatigue life of each rotary shoulder connection of a typical drill string. This can reduce the frequency of repairing the connection in the field and the frequency of having to pull up due to downhole damage.

  One of the cold valley bottom rolling product lines is Cutting Tools, Inc. 5050 Ashley Court, Houston, Texas 77041.

  Accordingly, it is generally desirable to provide an improved apparatus for performing cold valley bottom rolling on freshly cut and recut screws of an object.

Knight, M.J., Brennan, F.P. and Dover, W.D., “Fatigue Life Improvement of Threaded Connections by Cold Rolling”, Journal of Strain Analysis, vol. 40, pp.83-93 (September 30, 2004)

  Insertion reference signs for corresponding parts, portions or surfaces of the disclosed embodiments are for illustrative purposes only and are not limiting in any way. The present invention is not intended for objects such as pipes (O). An improved apparatus (20) for valley bottom rolling of screws (T), and more particularly, for cold valley bottom rolling is provided.

  In one form, the improved apparatus includes a body (21) having a passage (22) and having a cylindrical opening (23) in communication with the passage, and a body for sealingly sliding within the passage. An accumulator piston (24) attached to the body, a coarse adjustment screw (25) screwed to the body, an elastic member (26) acting between the coarse adjustment screw and the accumulator piston, and a cylindrical An actuator piston (28A, 28B) attached to the body for sealing and sliding within the opening, wherein a chamber (29) is defined in the passage between the accumulator piston and the actuator piston; An actuator piston having a proximal end (30) facing into the chamber and having a distal end (31); and rotating to the actuator piston adjacent to the distal end. A wide range of thread rolls (32) that are attachably mounted; a body having a first opening (33) in communication with the chamber; and a fine adjustment screw (34) screwed to the body at the first opening; The chamber (29) is completely filled with liquid and selectively adjusts the position of at least one of the coarse adjustment screw (25) and the fine adjustment screw (34) with respect to the body volume and the fluid in the chamber. The pressure can be changed in a controllable manner. The device can be attached to the machine tool (35) and also performs valley bottom rolling on the object screw when the object (O) and the device (20) are rotated relative to each other. Thus, it can move selectively toward the object.

  The body can have an abutment surface (44) surrounding a portion of the passage (22) to limit movement of the accumulator piston (24) away from the coarse adjustment screw (25).

  The position of the coarse adjustment screw (25) relative to the abutment surface (44) can be selectively adjusted to change the force on the accumulator piston (24) exerted by the elastic member (26).

  The position of the coarse adjustment screw (25) relative to the abutment surface (44) is adjusted so that the elastic member (26) applies a substantially constant force to the accumulator piston (24) as a function of the displacement of the elastic member. be able to.

  The elastic member can include a disc spring (41) or a disc spring stack.

  The body can have a second opening (36) in communication with the chamber (29), and the apparatus is a pressure gauge operably disposed in the second opening to sense pressure in the chamber. (39) can be included.

  The body can have a third opening (38) in communication with the chamber (29), and a closure plug (40) can be threadedly engaged with the body to close the third opening. .

  The improved device can be used to perform valley bottom rolling on the female thread or male thread (T) of the object (O).

  The device (20) can be attached to the machine tool (35) without connecting any external fluid to the device.

  Accordingly, it is a general object of the present invention to provide an improved apparatus for performing valley bottom rolling on threads of objects such as pipes.

  Another object can be attached to the machine tool and against the object to perform valley bottom rolling on the object's screw when the object and the device are rotated relative to each other. It is an object to provide an improved device for performing valley bottom rolling on a screw of an object that is movable and does not require any external fluid connection.

  These and other objects and advantages will become apparent from the foregoing and following specification, drawings and appended claims.

1 is a right end view of a first form of an improved apparatus for performing cold valley bottom rolling on a male thread of an object. FIG. FIG. 2 is a longitudinal vertical partial cross-sectional view, approximately cut along line 2-2 of FIG. 1, showing the screw roll engaging the male thread of the object. FIG. 6 is a right end view of a second embodiment of an improved apparatus for performing cold valley bottom rolling on an internal thread of an object. FIG. 4 is a longitudinal vertical partial cross-sectional view, roughly cut at line 4-4 of FIG. 3, showing the screw roll engaging the female thread of the object. FIG. 3 is a longitudinal vertical partial cross-sectional view of the body showing the accumulator piston and coarse adjustment screw in a state of being disassembled and aligned with the body. FIG. 6 is an enlarged detail view of a portion of the body in the circle shown in FIG. 5, showing the retaining ring in an exploded state aligned with the cylindrical opening. FIG. 6 is an enlarged detail view of another portion of the body within the circle shown in FIG. 5, showing the fine adjustment screw disassembled and aligned in line with the first opening of the body. FIG. 5 is an isometric view of the short actuator piston shown in FIG. 4. FIG. 9 is a plan view of the short actuator piston shown in FIG. 8. FIG. 9 is a left side view of the short actuator piston shown in FIG. 8. FIG. 9 is a right end view of the short actuator piston shown in FIG. 8. FIG. 3 is an isometric view of the long actuator piston shown in FIG. 2. FIG. 10 is a plan view of the long actuator piston shown in FIG. 9. FIG. 10 is a left side view of the long actuator piston shown in FIG. 9. FIG. 10 is a right end view of the long actuator piston shown in FIG. 9.

  First, it should be clearly understood that throughout the several figures, like reference numerals are intended to identify the same structural element, portion or surface throughout. This is because such elements, portions or surfaces are further described or explained throughout the specification and this detailed description is an integral part thereof. Unless indicated otherwise, the drawings are intended to be read in conjunction with the specification (eg, cross-hatching, component placement, proportions, degrees, etc.) and are considered part of the entire written description of the invention. Should. As used in the following description, the terms “horizontal”, “vertical”, “left”, “right”, “top”, and “bottom”, and their adjective and adverbial derivatives (eg, “ “Horizontal”, “rightward”, “upwardly”, etc.) simply refers to the orientation of the illustrated structure as the particular drawing faces the reader. Similarly, the terms “inside” and “outside” generally refer to the orientation of a surface relative to its extension or rotation axis, as appropriate.

  Referring now to the drawings, the present invention provides an improved apparatus 20 for performing valley bottom rolling, more specifically cold valley bottom rolling, on a thread T of an object O. The object may be, for example, a pipe having a female screw and a male screw at both edge ends. However, while this is an example, the present invention contemplates that this improved apparatus can be used with other types of objects as well.

  A first configuration of the improved apparatus is shown in FIGS. 1 and 2, and a second configuration of the apparatus is shown in FIGS. A first configuration of the device is shown as operably performing valley bottom rolling on the male thread of the object, and a second configuration of the device is illustrated as performing valley bottom rolling on the female thread of the object.

  2 and 4 are substantially the same except that the device shown in FIG. 2 uses a long actuator piston 28A and the device shown in FIG. 4 uses a short actuator piston 28B.

  The main body of the device shown in FIG. 4 is identical to the main body of the device shown in FIG. 2, except that it is arranged as a mirror image of the main body of the device shown in FIG. is there.

  Yet another difference is that the pressure gauge, fine adjustment screw and closure plug are threaded into different openings in the body in FIGS. 2 and 4 as described below.

  In other respects, the apparatus shown in FIGS. 2 and 4 is the same. For this reason, the same reference numerals are used in the following description to describe the corresponding structures of both forms of the device.

  Referring now to FIGS. 2, 4 and 5, the improved device, generally indicated at 20, has a horizontally elongated body 21 as shown, which includes an axial passage 22. And is shown as having a cylindrical opening 23 in communication with the passage.

  The accumulator piston 24 is attached to the body for sealing and sliding within the right edge end of the passage. The coarse adjustment screw 25 is attached to the right edge of the main body with a screw. An elastic member, indicated generally at 26, acts between the coarse adjustment screw and the accumulator piston.

  Actuator piston 28 is attached to the body for sealing and sliding within a cylindrical opening. Here, the subscripts “A” and “B” refer to specific structures of the long actuator piston and the short actuator piston, respectively. Thus, the long actuator piston is shown at 28A in FIG. 2, and the short actuator piston is shown at 28B in FIG. A chamber 29 is defined in the passage between the accumulator piston and the actuator piston and in a cylindrical opening. The actuator piston has a proximal end 30 facing into the chamber 29 and a distal end 31.

  A smooth tool steel thread burnishing roll 32 is rotatably mounted on the actuator piston adjacent the distal end of the actuator piston. The screw roll has a contour shape that is complementary to the contour shape of the screw to be rolled. The body has a first opening 33 in communication with the chamber. The fine adjustment screw 34 is screwed to the body at this first opening in FIG. Chamber 29 is completely filled with a suitable liquid. The position of at least one of the coarse adjustment screw 25 and the fine adjustment screw 34 relative to the body can be selectively adjusted to controllably change the volume of the chamber and thus the fluid pressure therein.

  The device can be operably attached to a machine tool, the fragment of which is indicated at 35 in FIGS. 2 and 4, and when the object and the device are rotated relative to each other, The object can be selectively moved toward the object so as to perform valley bottom rolling on the screw of the object.

  The device is further shown as having a second opening 36 and a third opening 38 provided in the body in communication with the chamber. The second and third openings are identical, so that the pressure gauge and the closure plug can be threadedly engaged with the body interchangeably in either of these openings as described below. The pressure gauge 39 is screwed to one of the second and third openings to monitor the pressure in the chamber 29. A closure plug 40 is attached to the other of the second and third openings to seal the chamber. In the embodiment of FIG. 2, the pressure gauge 39 is shown as being operably attached to the second opening 36 of the body, and the closure plug 40 is operably attached to the third opening 38 of the body. Shown as installed. The main body shown in FIG. 4 is a mirror image of the main body shown in FIG. However, in this arrangement, the pressure gauge 39 is shown as being attached to the third opening 38 of the body and the closure plug is shown as being attached to the second opening 40 of the body. .

  The elastic member 26 is shown as a disc spring laminate having a plurality of disc springs denoted by reference numeral 41 as a single unit. The disc spring stack is arranged to act between the coarse adjustment screw and the accumulator piston. The left end of the accumulator piston is disposed in contact with the contact surface 44 in the main body, and restricts leftward movement with respect to the main body. The coarse adjustment screw can be screwed into the body passageway to selectively change the preload of the disc spring stack. In the preferred embodiment, the Belleville spring stack operates in the linear portion of the force characteristics for its displacement. Optionally, the Belleville spring stack can be preloaded in a region where the force versus displacement characteristic is substantially horizontal, regardless of its displacement. This effectively means that a substantially constant force is applied to the accumulator piston when the disc spring laminate is subjected to such preloading. In other words, the accumulator piston can be displaced in the right direction against the bias of the disc spring stack with a substantially constant force regardless of the displacement of the spring stack.

  Referring now to FIGS. 5-7, the body is shown in more detail as a specially configured horizontally elongated member having a longitudinal axis xx. The passage 22 includes a large-diameter cylindrical portion 42 that extends leftward from the right end surface 43 into the body, has a frustoconical abutment surface 44 facing inwardly in the right direction, and another cone facing inwardly in the right direction. It is shown as having a trapezoidal abutment surface 45 and a small diameter dead end cylindrical portion 46 extending leftward therefrom. As best shown in FIG. 6, the cylindrical opening 23 is a relatively large diameter hole drilled through the body at a depression angle of about 85 ° which is less than a right angle to the body axis xx. It is. The dead end passage 22 communicates with the cylindrical opening 23 by a communication passage 48.

  A cylindrical end cap 49 is disposed in the cylindrical opening 23 and is held in this position by a retaining ring 50, which retains the annular groove 47 extending radially from the surface 23 into the body. Snapped inside. Annular groove 51 extends into the retaining ring radially and houses and receives an O-ring 52 that sealingly engages the wall surface of the cylindrical opening.

  As best shown in FIG. 7, the first, second and third openings 33, 36, 38 each extend into the body and communicate with the chamber 29. Each of these openings is internally threaded to receive a suitable device, such as a fine adjustment screw, pressure gauge 39, or closure plug 40, as shown in FIGS. The threaded hole 53 extends rightward from the left end face 54 into the body and receives and receives a set screw 55. The right end of the set screw 55 is received in a key groove 56 provided in the actuator piston. This key-to-keyway coupling between the set screw 55 and the actuator piston keyway 96 limits the movement of the actuator piston relative to the body along the axis yy of the cylindrical opening.

  Referring now to FIG. 5, the accumulator piston 24 has an annular vertical left end surface 58, an annular vertical right end surface 59, and an outer surface, the outer surfaces in turn toward the abutment surface 44 of the body. A frustoconical surface 60 facing leftward and adapted to selectively engage with it, and a horizontal cylindrical surface 61 provided with an annular groove 62 for receiving an O-ring. The O-ring causes the accumulator piston to slide in a sealed manner in the cylindrical portion 42 of the passage, the cylindrical surface 61, the annular vertical surface 63 facing rightward, and the outer edge of the right end surface 59 following the rightward direction. And a horizontal cylindrical surface 64 leading to The threaded blind hole 65 extends from its right end face into the accumulator piston.

  As best shown in FIGS. 2 and 4, the shoulder screw 66 can be positioned to act between the coarse adjustment screw 25 and the accumulator piston 24.

  Turning now to FIG. 5, the coarse adjustment screw 25 is a specially configured horizontal elongated member having an annular vertical left end surface 67, an annular vertical right end surface 68, and an outer surface. The outer surfaces are, in order, a horizontal cylindrical surface 69 extending rightward from the outer edge of the left end surface 67, an annular vertical surface 70 facing left, a horizontal cylindrical surface 71, and a screw of the main body. 73 includes a male threaded portion 72 configured to mesh with 73, an annular vertical surface 74 facing rightward, and a horizontal cylindrical surface 75 connected to the outer edge of the right end surface 68 following the rightward direction. A stepped hole extends axially through the coarse adjustment screw. This hole has an inwardly extending horizontal cylindrical surface 76 extending rightward from the inner edge of the left end surface 67, an annular vertical surface 78 facing leftward, a short cylindrical surface 79, and an annular shape facing rightward. It is shown as being defined by a vertical surface 80 and a horizontal cylindrical surface 81 that continues to the right and continues to the inner edge of the right end surface 68.

  As best shown in FIG. 7, the fine adjustment screw 34 is a vertically elongated plug-like member having a lower circular surface 83, an upper horizontal circular surface 84, and an outer surface, the outer surfaces being in turn, A male threaded portion 85 extending downward from the outer edge of the upper end surface 84 and configured to mesh with the screw 37 of the main body, a frustoconical surface 86 facing outward in the downward direction, and an outer edge of the lower end surface 83 following the downward direction And a vertical cylindrical surface 88 connected to. An annular groove 89 extends within the fine adjustment screw adjacent to the lower end surface of the fine adjustment screw to receive and receive an O-ring that allows the fine adjustment screw to be sealed to the body at the appropriate body opening. Can be attached. The polygonal hole extends downwardly from its upper surface 84 into the fine adjustment surface to receive and house a suitable rotating tool (eg, an Allen wrench), thereby screwing into the body and engaging the body. Or disengage.

  In FIG. 2, the long actuator piston is indicated by 28A. In FIG. 4, the short actuator piston is indicated by 28B. Piston 28A is longer than piston 28B, but these two actuator pistons are substantially the same. Long actuator pistons are shown in more detail in FIGS. 9-9C, and short actuator pistons are shown in more detail in FIGS. 8-8C.

  Referring initially to FIGS. 8-8C, the short actuator piston is shown as having a circular vertical left end face 90B facing left and two bifurcated legs 91B, 92B extending respectively to the right. It is. The piston has a horizontal cylindrical surface 93B facing outwardly with an annular groove 94B for receiving and receiving an O-ring. The straightly aligned holes 95B, 95B extend through the bifurcated legs 91B, 92B and receive and accommodate roll pin shafts (not shown). A horizontal elongate groove 96B extends from and into the actuator piston surface 97B to receive and receive the tip of the screw 55. The bore 98B extends into the actuator leg 92B from the right end surface to receive and receive a set screw (not shown), and the roll shaft can be secured to the actuator pin by the set screw. The actuator piston is further shown as having a flat surface 99B.

  A long actuator piston is shown in FIGS. 9-9C. This actuator piston is simply elongated with respect to the short piston shown in FIGS. Thus, the long piston has the same parts as described above for the short piston, but these parts are indicated by the subscript “A” rather than “B”.

  Accordingly, the present invention broadly provides an improved device (20) for performing valley bottom rolling on the screw (T) of the object (O), the improved device (20) comprising a passage (22). A body (21) having a cylindrical opening (23) in communication with the passage, an accumulator piston (24) attached to the body for sealing and sliding in the passage, and a screw on the body A coarse adjustment screw (25) mounted on the body, an elastic member (26) acting between the coarse adjustment screw and the accumulator piston, and attached to the body for sealing and sliding in a cylindrical opening. Actuator piston (28A or 28B). A chamber (29) is defined in the passage between the accumulator piston and the actuator piston. The actuator piston has a proximal end (30) facing into the chamber and a distal end (31). A screw roll (32) is rotatably attached to the actuator piston adjacent to the distal end of the actuator piston. The body has a first opening (33) in communication with the chamber. The fine adjustment screw (34) is screwed to the body at the first opening. The chamber is completely filled with a suitable fluid, such as a relatively incompressible liquid. The position of at least one of the coarse and fine adjustment screws relative to the body can be selectively adjusted to controllably change the fluid pressure in the chamber. The device can be attached to a machine tool (35) and the object is oriented to perform valley bottom rolling on the object screw when the object and the device are rotated relative to each other. You can move selectively.

  By information and belief, the present invention has many patentable features over the prior art. These include: (1) the use of self-contained pressure generators and accumulators, (2) a unique system that determines the orientation of the rolls, (3) the use of digital pressure devices, and (4) measurement of forces that do not require conversion. Including.

  Regarding the first point, there is no known prior art that uses a self-contained pressure generator or a self-contained fluid accumulator. This eliminates the need for external pressure pumps, external accumulators, and various hose fittings, desorption joints, and valves. This simplifies installation and use and eliminates many clutter from the machine tool work area.

  Regarding the second point, no known prior art reference has a system for ensuring the correct orientation of the screw burnishing roll with respect to the pre-cut thread profile of the workpiece. The shape of the workpiece thread is symmetrical with respect to a line perpendicular to the main axis of the workpiece screw. Because the roll holder has an inclination of 85 °, the screw burnishing roll has an asymmetric profile that is offset by 5 ° on one side to compensate for the 5 ° inclination of the roll holder. With all known prior art devices, great care must be taken to avoid mounting the roll in the opposite position. If the roll is not installed in the correct orientation, the burnishing operation can cause significant damage to the screw and the workpiece must be reworked or discarded. In known prior art devices, this orientation is only visual confirmation and it is difficult to identify small angle tilts.

  On the other hand, the Applicant's improved fixture uses an asymmetric roll holder in conjunction with the asymmetric hub shape of the roll itself to ensure that the roll is attached to the fixture only in the proper orientation. In the preferred embodiment, a slight step of about 0.38 millimeter (0.015 inch) on the side wall of the roll mounting pocket is used, which is located some distance (r) in the radial direction from the centerline of the roll mounting axis. . There is no such step on the opposite wall. This is clearly shown in FIGS. 8A and 9A. In the preferred embodiment, two different hub diameter rolls are used on both sides. The radius of one hub is slightly shorter than the radial distance (r). The radius of the other hub is slightly longer than the radial distance (r). When inserting a roll with these asymmetrical hubs into a stepped receiving pocket, the roll is correctly aligned with the roll pin axis only if the smaller hub is adjacent to the step. If the roll pin is inserted so that the larger hub is adjacent to the step, the hub contacts the step before aligning the roll shaft with the roll pin hole shaft, so the roll pin profile may be inserted incorrectly. Is prevented.

  In the preferred embodiment, two hubs of different sizes are used on both sides of the roll, but those skilled in the art will appreciate that other configurations will prevent the same purpose, i.e., improperly inserting the roll into the pocket. It will be readily understood that the objective can be achieved. Some alternatives include, but are not limited to, providing two steps at the receiving portion with different radial distances, using a tapered roll hole in conjunction with a tapered roll shaft, Use of a roll hole with a step with the roll axis, a pocket of a roll having a minimally large contour shape, etc., similar to the asymmetrical thread shape of the roll.

  Regarding the third point, there is no known prior art using a digital pressure monitoring device. All known prior art devices appear to use an analog pressure gauge with a dial indicating instantaneous pressure as an accessory. In order to read the instrument, the user must be in the immediate vicinity of the instrument, typically no more than about 91 centimeters (36 inches), as far as can be seen. The instrument reading is only the instantaneous pressure at that time. Therefore, as required by the standards applied to pipes used in the oil industry, the user is required to monitor the pressure in the work cycle as soon as large parts move and where the lubricant is sprayed. It is a harmful environment for the user. This violates the OSHA standard for safety.

  Applicant's device uses a digital meter with minimum / maximum calling capability, allowing the user to monitor pressure from a more remote and safe distance. The user does not attempt to locate the small needles that fluctuate significantly between the fine scales, but digitally attenuates the large text values through the windows in the machine's housing and backlit. You can read on the display with. The improved digital pressure gauge is equipped with a min / max calling function. The pressure value reached during rolling is recorded and can be seen after the fact once the machine has stopped moving and it is safe to approach the fixture. With Option b's wireless pressure transducer set, the pressure is more remote, such as on the display outside the machine's housing, or at an office elsewhere in the manufacturing facility or via the Internet at the customer's location. Even the location can be continuously monitored and recorded remotely. Pressure values can also be recorded to track the serial number of the component being processed, providing traceability to end users and regulatory agencies.

With respect to the fourth point, there is no known prior art that does not require the indicated pressure value to be converted into a pounding value of the burnishing force. Standards applied to this cold valley bottom rolling operation, specifically, T.I. H. The Hill Standard DS-1 requires that a minimum force be applied to each of the various screw sizes. However, since prior art devices do not have a means of directly measuring force, instead they typically measure hydraulic pressure and then use a chart to convert the recorded pressure into a calculated force value. . In Applicant's device, the pressure is also recorded. However, the surface area of the working piston is dimensioned to be exactly about 6.45 cm ² (1 in ² ), and the pressure values are in pounds of force without the need for scaling or conversion. A pressure of about 6.89 kPa (1 psi) is equivalent to a force of about 4.45 Newtons (1 pound). This simplifies operation and also eliminates potential sources of calculation errors.

Modifications The present invention explicitly contemplates that many changes and modifications can be made. For example, the material of the composition does not seem important. The length of any part, as well as its ratio and degree to another part, does not seem important. The passages and chambers may be formed in a manner different from that shown here. The object is not limited to a pipe.

  The elastic member may be a gas pressure device filled with a filling gas such as a disc spring, a disc spring laminate, a die spring, a machined spring, a bellows, or nitrogen.

  Accordingly, although two forms of improved valley floor rolling devices have been shown and described, and some variations and modifications thereof have been described, those skilled in the art will be able to define and differentiate between the following claims. It will be readily appreciated that various additional changes and modifications can be made without departing from the spirit of the invention as described.

Claims (13)

An apparatus for rolling a valley bottom on a screw of an object,
A body having a passage and having a cylindrical opening in communication with the passage;
An accumulator piston attached to the body that slides sealingly within the passage;
A coarse adjustment screw attached to the body with a screw;
An elastic member acting between the coarse adjustment screw and the accumulator piston;
An actuator piston attached to the body that slides sealingly within the cylindrical opening, wherein a chamber is defined in the passage between the accumulator piston and the actuator piston; An actuator piston having a proximal end facing the chamber and having a distal end;
A screw roll rotatably attached to the actuator piston adjacent to the distal end;
The body having a first opening in communication with the chamber;
A fine adjustment screw screwed to the body at the first opening,
The chamber is completely filled with liquid;
Selectively adjusting the position of at least one of the coarse and fine adjustment screws relative to the body to controllably change the fluid pressure in the chamber;
Thereby, the device can be mounted on a machine tool and, when the object and the device are rotated relative to each other, perform a valley bottom rolling on the screw of the object. Can be selectively moved towards the object;
apparatus.   The apparatus of claim 1, wherein the body has an abutment surface surrounding a portion of the passage to limit movement of the accumulator piston in a direction away from the coarse adjustment screw.   The apparatus of claim 2, wherein the position of the coarse adjustment screw relative to the abutment surface can be adjusted to change the force applied to the accumulator piston applied by the elastic member.   4. The apparatus of claim 3, wherein the position of the coarse adjustment screw relative to the abutment surface is adjusted such that the elastic member applies a force to the accumulator piston as a function of displacement.   The apparatus of claim 4, wherein the elastic member comprises a disc spring.   The body has a second opening in communication with the chamber, and the apparatus includes a pressure gauge operably disposed in the second opening to sense pressure in the chamber; The apparatus of claim 1.   The apparatus of claim 6, wherein the pressure gauge is digital and has a min / max calling function.   The apparatus of claim 7, wherein the pressure gauge includes a transmitter that transmits the indicated pressure to a remote location.   The apparatus of claim 7, wherein the accumulator piston is dimensioned to indicate a pound of force applied by the pressure gauge.   7. The body of claim 6, wherein the body has a third opening in communication with the chamber and further comprising a plug, and the plug is threadedly engaged with the body to close the third opening. apparatus.   The apparatus according to claim 1, wherein the apparatus can be used to perform valley bottom rolling on an internal thread or external thread of the object.   The device of claim 1, wherein there is no external fluid connection to the device.   The apparatus of claim 1, wherein the screw roll cannot be improperly attached to the actuator piston.